At the recent European Skyrunning championships in the rugged beauty of the Italian Dolomites, Sweden won three individual medals; two gold and one silver. An impressive tally, certainly. But consider that this medal haul was the result of the performances of just one athlete. An athlete who, a little over a year ago, was almost completely unknown, even within the close-knit trail and mountain running scene. Her name is Emelie Forsberg.

Orienteering, trekking, climbing, skiing, foraging for mushrooms and berries have been an integral part of her life since she was very young. When the 26-year-old began running trails five years ago it was a natural transition – a basic desire to move quickly over steep and technical terrain. It was, more than anything else, unbridled fun. Then, after victories at some local races last year, she joined the Swedish Salomon team and was asked to accompany the international team for a week-long training retreat in Greece. She made an immediate impression and has been an integral part of the team ever since.

"I love her joie de vivre, her simplicity, her relationship with nature," says Greg Vollet, manager of the Salomon Trailrunning team. Her leftfield and, at times, downright quirky approach to training and racing is at the core of what makes her so special – take her first mountain-marathon win in 2010, which was achieved after taking a long, mountain-top break to eat some chocolate cake that she had brought along. Or the time when, at the end of her breakthrough season last year, Vollet enquired as to what her plans were for the next year. "She started to talk to me about climbing projects; she didn't talk to me about running at all. I was speechless," he says with a laugh. Forsberg's running successes are not the primary goal, it seems, rather a simple by-product of her deep-rooted love for moving fast in the mountains, and, damn, does she move fast.

Such has been Forsberg's speed through and above the tree-line, such has been the swathe she has cut through the Skyrunning circuit on the mountain ranges of Europe this summer, that she has placed in the top 10 overall in a number of the races she has competed in. She is spearheading a new era for the sport, where younger runners, both women and men, are dominating. It's something that was unheard of until quite recently as Lauri Van Houten, vice president of the International Skyrunning Federation (ISF) explains. "We have seen in recent years very young runners do amazing things," she says. "This was unheard of 10, 20 years ago when the runners doing this sport were more mature." Forsberg is the face of this new era – to see her beaming on the finish line after running 80km across a series of high-altitude summits would make even the most ardent ultra-doubters, ponder. "Why does she look like she's actually having fun?" Well, the fact is she is. As Van Houten puts it, "I've rarely seen such unbounded love of the mountains in anyone."

Emelie Forsberg at the finishing line, winning her second gold at the Trans d'Havet Ultra SkyMarathon at the European Skyrunning Championships Photograph: droz-photo.com

Forsberg currently calls the Norwegian city of Tromso, deep inside the arctic circle, her home. It's a place where the sun disappears behind the cities surrounding mountains for two months of the year, between late November and late January – the "polar night". This is her beloved Nordic bolthole, the place where she'll withdraw to when the racing season winds down and it's time to reflect on another amazing year. It offers her peace, quiet and a well-earned opportunity to recuperate. A time to partake her other passion – baking sourdough bread, buns stuffed with cardamom and cinnamon and chocolate cake. A time, simply, to breathe and unwind. Greg Vollet remembers his first encounter with Forsberg: "Emelie said: 'You know, I always put on a little weight during the winter because it is dark and cold all day at home, so we do not go outside so much, we spend our time in pubs drinking beer.' I immediately appreciated her state of mind." For Forsberg, you see, the contrasts are what's appealing – work and play, summer and winter, fast and slow, ascent and descent. Change and diversity seem to bring about the best from her.

When she won her first ultra trail race, the TNF 50 mile in San Francisco late last November, I likened Forsberg to the aurora borealis: she makes an appearance, blows people's minds and then disappears back into the inky darkness of the northern European winter. What we've witnessed this summer, however, is something else entirely – she has lighted up the trails and peaks in a continuous show of energy, power and warmth – like a running, smiling, skipping midnight sun.

• Forsberg's next race is the Matterhorn Ultracks – the fourth race of the Skyrunning Sky Series, on Saturday 24 August 2013. Visit ultraks.com for more details.